Air propeller



Dec- 1935- J. D. MICHAUD AIR PROPELLER Filed Aug. 12, 1933 2 Sheets-Sheet 1 p 7 MM m m mm m WM m p, 2 Z i JW '5 w. y I JZ I M9 1 ATTORNEYS J. D. MICHAUD AIR PROPELLER Filed Aug; 12, 1933 axis of the propeller.

Patented Dec. 17, 1935 PATENT OFFICE AIR PROPELLER Joseph D. Michaud, Santa Cruz, Calif.; Katherine Michaud administratrix of said Joseph D.

Michaud, deceased 7 Application August 12, 1933, Serial ."No. 684,799%

8 Claims.

My invention relates to improvements in air propellers, and it consists of the combinations, constructions and arrangements hereinafter described and claimed.

An object of my invention is to provide an airplane propeller in which the airplane blades are inclined and each has one or more control blades positioned in back of the airplane blade and having a surface which extends at right angles to the I have found that the placing or" a control blade at the back of each propeller blade in the manner indicated causes the air flowing past the propeller to slow up, and to be compressed, this compressed air acting against the rear surface of the propeller blade for causing it to create a greater pulling force than it otherwise could. The control blade not only slows up the air and compresses it, but also causes the air to spread out over the rear surface of the propeller blade, and this permits the area of the propeller blade to be greatly increased over that of standard practice. The number of revolutions per minute of the propeller blade with this attachment can be materially reduced to about one-third or one-half of the former necessary speed. This will permit the engines operating the propellers to run slower and thus increase the life of the engine.

It will further be noted that due to the greater pulling effect on the propeller blades the speeding up of the engine when starting the airplane will not be necessary because the propeller will take hold of the air more effectively than heretofore and will move the load more quickly.

The device is extremely simple in construction and does not have any moving parts, and therefore the life of the device can equal the life of the propeller blade.

Other objects and advantages will appear in the following specification, and the novel features of the device will be particularly pointed out in the appended claims.

My invention is illustrated in the accompanying drawings forming a part of this application, in

d which Figure 1 is a plan view of an airplane propeller showing two control blades connected to each propeller blade;

Figure 2 is an end view of Figure 1;

Figure 3 is a section along the line 3-3 of Fig. 1;

Figure 4 shows an end view of one of the control blades and a portion of its associate propeller blade;

Figure 5 is a plan view of the modified form of the invention;

Figure 6 is an end view of Figure 5; and

Figure '7 is a side elevation of Figure 5.

In carrying out my invention I provide a propeller mounted upon a propeller shaft l. The propeller comprises a hub 2, see Figure 3, that is rigidly secured to the shaft, and the hub carries a frame 3. Struts 4 are connected to the frame 3 and are bent rearwardly for a short distance, 10 and then are extended radially as at 5, from the propeller shaft I. Additional struts 6, see Figures 'l and 2, extend radially from the front of the hub '2 and are not bent rearwardly as is true of the struts A. Propeller blades 1 of a wider area than a normal propeller blade are secured to the struts .6, and to the radially extending porticns 5 of the struts 4. The propeller blades 1 are :inclined in the manner shown in Figure 2, and their leading edges 8 are secured to the struts.

I provide :two sets of control blades and in Figure 1 I show control blades 9 being disposed in back of the propeller blades 1 and the leading edges 1-110 of thecontrol blades -.are disposed ad- Vance of the leading edges .8. The control blades 9 are shaped in the manner shown in Figure l, and Figure 3 shows how the mid-portion ll of the control blades -.9 passes between the struts A and is secured to the frame 3 by rivets I2 or other '30 suitable fastening means. If desired the .midportion ljl may be dispensed with.

The control blades are secured to the propeller blades by brackets I3, and these brackets are shaped in the manner shown in Figure 4. If desired the brackets may be provided with-openings I o permit air topass therethroush.

One set of control blades 9 may be used, or if desired another set may also be used. I have shown two sets in Figures 1, 2 and 3, and the 40 second set of control blades l5 are also disposed in back of the propeller blades 1, and are mounted a greater distance away from the front of the hub than are the control blades 9. The control blades 15 have an intermediate portion I6 that extends through the struts 4, see Figure 3, and the ends of the blades are secured to the propeller blades by brackets H. In Figure 2 I show the brackets l3 and IT as not being provided with openings, although the brackets may be provided with openings in the same manner as shown in Figure 4, if desired. It will be noted in Figure 2 that the rear edges ll of the propeller blades are disposed further away from the front of the hub than are the control blades IS, The bracing ring [8 may be secured to the radial portions of the struts 4 if desired.

In Figures 5 to '7 inclusive I show another propeller in which the propeller blades l9, are more in the shape of a standard propeller blade. These blades are connected. to a central hub which in turn is mounted upon the propeller shaft I. In this form of the device the tips of the propeller blades are curved rearwardly as at 29. The control blades 2! are secured to the propeller blades i9 by brackets 22, and it will be noted from Figure 5 that the control blades 2| do not extend to the ends of the propeller blades. In the form of the device shown 'in Figure 1 the control blades do extend to the ends of the propeller blades.

The control blades have a central portion 23 that is secured to the hub 20, and in this way the control blades 21 are given additional support. If desired struts 2 5 may extend between the brackets 22 to provide additional strength.

In both forms of the invention the leading edge of the control blade is in advance of the leading edge of the propeller blade. The rotation of the propeller is indicated by the arrows.

From the foregoing description of the various parts of the device, the operation thereof may be readily understood.

It is the purpose of this invention .to slow up the air after it passes the propeller blades to such a point that the air immediately in back of the rear surface of the propeller blades will be compresssed, and this compressed air will be acted upon by the propeller blades and afford a greater pulling action than is possible with a standard propeller. The control blades extend at right angles to the propeller shaft I and are positioned in back of the propeller blades so as to act upon the air as it leaves the propeller blades and to throw this air beneath the rear surface of the blades. This permits the propeller blades to be increased in area and also permits the speed of the propeller to be reduced.

I claim:

1. An airplane propeller comprising inclined blades and control blades disposed in back of the first blades and extending at right angles to the propeller axis.

2. An airplane propeller comprising inclined blades and control blades disposed in back of the first blades .and extending at right angles to the propeller axis, said control blades starting from the center of the propeller and extending substantially throughout the length of the propeller blades.

3. An airplane propeller comprising inclined blades and control blades disposed in back of the first blades and extending at right angles to the propeller axis, said control blades starting from the center of the propeller and extending substantially throughout the length of the propeller blades, the leading edge of the control blades be- 5 ing slightly in advance of the leading edge of the propeller blade.

4. An airplane propeller comprising inclined propeller blades, control blades disposed in back of the first blades and extending at right angles to the propeller axis, the outer end of each control blade having a bracket connecting it with its associate propeller blade, the bracket being arcuate in shape and cooperating with the control blade for spreading the air against the rear of 1 the propeller blade for increasing the pull of the propeller in the air.

5. An airplane propeller comprising a hub, blades extending from the hub and being inclined at an angle for screwing into the air when the 2 propeller is rotated, and a control blade extending through the hub and having the portions, projecting from the hub, disposed in the back of the inclined blades, the plane of the projecting portions of the control blade extending at right 25 angles to the axis of the propeller.

6. An airplane propeller having inclined blades of a relatively large area, control blades disposed in back of the front portions of the inclined blades and extending at right angles to the axis of the propeller, said control blades having leading edges in advance of the leading edges of the inclined blades, and a second set of control blades disposed in back of the first-named control blades and being positioned substantially midway between the front and rear edges of the inclined blades, the rear edges of the inclined blades being further back from the leading edges of the same blades than the second set of control blades.

'7. An airplane propeller having inclined blades with rearwardly curved ends, and control blades disposed in back of the inclined blades and extending at right angles to the axis of the propeller, the leading edges of the control blades being in advance of the leading edges of the inclined blades While the rear edges of the inclined blades are further removed from the leading edges of the same blades than are the control blades.

8. An airplane propeller comprising propeller blades, control blades disposed in back of the propeller blades, and brackets connecting the control blades to the propeller blades for supporting purposes, said brackets also cooperating with the control blades for spreading the air against the rear of the propeller blades for increasing the pull of the propeller in the air.

JOSEPH D. MICHAUD. 

